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Thursday, July 15, 2010

PEACOCK


The peafowl are the three species of bird in the genera Pavo and Afropavo of the pheasant family, Phasianidae. They are most notable for the male's extravagant tail, a result of sexual selection, which it displays as part of courtship. The male is called a peacock, the female a peahen.

The male (peacock) has beautiful iridescent blue-green or green coloured plumage. His tail feathers have a series of eyes that are best seen when the tail is fanned. Both species have a head crest.

The female (peahen) has a mixture of dull green, brown and grey in her plumage. She lacks the long tail of the male, but has a crest.

Many of the brilliant colors of the peacock plumage are due to an optical interference phenomenon (Bragg reflection) based on (nearly) periodic nanostructures found in the barbules (fiber-like components) of the feathers.

Different colors correspond to different length scales of the periodic structures. For brown feathers, a mixture of red and blue is required?one color is created by the periodic structure, while the other is a created by a Fabry-Perot interference peak from reflections off the outermost and innermost boundaries of the periodic structure.

Such interference-based structural color is especially important in producing the peacock's iridescent hues (which shimmer and change with viewing angle), since interference effects depend upon the angle of light, unlike chemical pigments.

In captivity, the peafowl has produced many plumage color variations. Those are mutations that have been secured by selective breeding. They included: white bodied, barred winged, white eyed, pied, cameo, charcoal, bronze, opal, peach, midnight, purple, and any combination of these variations

The Indian Peafowl is native to India and Sri Lanka. The Green Peafowl breeds from Myanmar east to Java. The IUCN lists the Green Peafowl as vulnerable to extinction due to hunting and a reduction in extent and quality of habitat. The two Pavo species will hybridize.

The peafowl are forest birds which nest on the ground. They eat mainly seeds, but also some insects and fruit. The Pavo peafowl are terrestrial feeders, but roost in trees. They are reluctant fliers other than to access their roosts

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